I was planning on buying a 3 foot long 3 inch diameter quartz glass tubing to build a battery powered bong that changes colors using colored light bulbs at the base. i know PVC piping has ill effects on the water used in the bong i know its unlikely but i need confirmation that this will be okay.
Not likely. Caves are generally found in limestones where water sinking into the rock has dissolved channels that become big enough to be called caves. Limestone is made of calcium carbonate, CaCO3, and there is very little quartz in limestone in general. What grows in caves is usually stalactites and stalagmites that are made out of the calcium carbonate that has been dissolved by ground water moving through the limestones and then precipitated when it gets into the cave. Most quartz crystals are found where hot hydrothermal fluids have circulated underground, usually related to igneous activity or metamorphism. So someplace with granite or metamorphic rocks is best. But you need to do some research and find out the areas where quartz crystals are found. I know that some places in the Ozark mountains in Arkansas have a lot of quartz, and there are quarries where you can hunt for the crystals for a fee.
